Identifying novel drug targets to overcome resistance to tyrosine kinase inhibitors (TKIs) and eradicating leukemia stem/progenitor cells are required for the treatment of chronic myelogenous leukemia (CML). Here, we show that ubiquitin-specific peptidase 47 (USP47) is a potential target to overcome TKI resistance. Functional analysis shows that USP47 knockdown represses proliferation of CML cells sensitive or resistant to imatinib in vitro and in vivo. The knockout of Usp47 significantly inhibits BCR-ABL and BCR-ABLT315I-induced CML in mice with the reduction of Lin-Sca1+c-Kit+ CML stem/progenitor cells. Mechanistic studies show that stabilizing Y-box binding protein 1 contributes to USP47-mediated DNA damage repair in CML cells. Inhibiting USP47 by P22077 exerts cytotoxicity to CML cells with or without TKI resistance in vitro and in vivo. Moreover, P22077 eliminates leukemia stem/progenitor cells in CML mice. Together, targeting USP47 is a promising strategy to overcome TKI resistance and eradicate leukemia stem/progenitor cells in CML.
Drug Resistance, Neoplasm , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Protein Kinase Inhibitors/pharmacology , Ubiquitin Thiolesterase/metabolism , Ubiquitin-Specific Proteases/metabolism , Animals , Cell Proliferation/drug effects , DNA Damage , DNA Repair/drug effects , Drug Resistance, Neoplasm/drug effects , Extracellular Signal-Regulated MAP Kinases/metabolism , Fusion Proteins, bcr-abl , Gene Expression Regulation, Leukemic/drug effects , Humans , K562 Cells , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Mice, Knockout , Proteasome Endopeptidase Complex/metabolism , Protein Binding/drug effects , Protein Stability/drug effects , Proteolysis/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , STAT5 Transcription Factor/metabolism , Signal Transduction/drug effects , Thiophenes/pharmacology , Xenograft Model Antitumor Assays , Y-Box-Binding Protein 1/metabolism , ras Proteins/metabolism
Extranodal natural killer/T cell lymphoma, nasal type (ENK/TCL), is an aggressive and rare hematological malignancy. Patients with advanced and relapsed/refractory disease have very poor outcomes. In this study, we retrospectively assessed the efficacy and safety of MEDA regimen (methotrexate, etoposide, dexamethasone and pegaspargase) in the treatment of advanced and relapsed/refractory ENK/TCL patients. Thirteen patients received a total of 55 cycles of MEDA, with a median of four cycles. At the completion of treatment, the overall response rate was 76.9 %, with a complete response rate of 61.5 %. The 1-year overall survival rate was 69.2 %, and 1-year progression-free survival was 61.5 %. Treatment-related toxicity was monitored in all patients. Grade 3/4 neutropenia occurred in 46.2 % of patients. Serious infections happened in two cases (15.4 %). Grade 3/4 thrombocytopenia occurred in 30.8 % of patients, and 23.1 % received platelet transfusion. Grade 3/4 anemia was observed in 23.1 % of patients. Hepatotoxicity and low fibrinogen were common, but mild. These results show that MEDA regimen is very effective with tolerable adverse effects in the treatment of advanced and relapsed/refractory ENK/TCL. Further prospective trials are expected to validate the efficacy of MEDA in an expanded number of patients.
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Lymphoma, Extranodal NK-T-Cell/drug therapy , Lymphoma, Extranodal NK-T-Cell/pathology , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Asparaginase/administration & dosage , Dexamethasone/administration & dosage , Etoposide/administration & dosage , Female , Humans , Kaplan-Meier Estimate , Lymphoma, Extranodal NK-T-Cell/mortality , Lymphoma, Extranodal NK-T-Cell/radiotherapy , Male , Methotrexate/administration & dosage , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Polyethylene Glycols/administration & dosage , Retrospective Studies , Treatment Outcome
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an interferon (IFN)-induced molecule with apoptotic activity. We examined gene mutations in the death domains of TRAIL receptor 1 (TRAIL-R1) and TRAIL receptor 2 (TRAIL-R2), and in the TRAIL gene promoter in 46 chronic myelogenous leukemia (CML) patients. In 23 of the 46 patients, all the coding regions of TRAIL-R2 were also examined. However, no mutation or loss of heterozygosity was found. Furthermore, no mutation in the death domains of TRAIL-R1 and TRAIL-R2 genes, which causes amino acid change, was found in 18 myelodysplastic syndrome (MDS) patients. Ribonuclease protection assay (RPA) and real-time quantitative polymerase chain reaction using polymorphonuclear neutrophils of five new CML patients showed that the TRAIL mRNA expression was very low before in vitro IFN-alpha stimulation and markedly upregulated after IFN-alpha stimulation. FAS mRNA was also upregulated with IFN-alpha stimulation but the fold induction was far lower than that of TRAIL mRNA. In addition, RPA revealed that the ratio of (TRAIL-R1 plus TRAIL-R2) to TRAIL-R3 was also increased after IFN-alpha stimulation. Taken together, gene mutations of TRAIL-R1, TRAIL-R2 are infrequent in patients with CML and MDS. And so is the TRAIL promoter for CML. These mutations seem unrelated to tumorigenesis, disease progression, and response to IFN-alpha therapy in CML. A markedly high induction of TRAIL mRNA by IFN-alpha may have some relevance to IFN-alpha action in CML patients.
Amino Acid Substitution/genetics , Gene Expression Regulation, Leukemic/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Loss of Heterozygosity/genetics , Myelodysplastic Syndromes/genetics , Receptors, Tumor Necrosis Factor/genetics , Apoptosis Regulatory Proteins , Female , Gene Expression Regulation, Leukemic/drug effects , Humans , Immunologic Factors/pharmacology , Immunologic Factors/therapeutic use , Interferon-alpha/pharmacology , Interferon-alpha/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Male , Membrane Glycoproteins/genetics , Middle Aged , Myelodysplastic Syndromes/drug therapy , Open Reading Frames/genetics , Promoter Regions, Genetic/genetics , Protein Structure, Tertiary/genetics , RNA, Messenger/genetics , Receptors, TNF-Related Apoptosis-Inducing Ligand , TNF-Related Apoptosis-Inducing Ligand , Tumor Cells, Cultured , Tumor Necrosis Factor-alpha/genetics
We describe a patient with chronic myelogenous leukemia (CML), in whom the DNA breakpoint in the BCR-ABL fusion gene was determined to result in a rare e13a3 (b2a3) transcript. The breakpoint in BCR was intron 13, which was 30 bp downstream from exon 13, and the breakpoint in ABL was intron 2, and was 46 bp downstream from exon a2. This case conforms to the mechanism of DNA breakage occurring within ABL intron 2, but not at 5' to ABL exon a2. With our review of this case and the literature, it seems that CML with the BCR-a3 fusion product is associated with a low proportion of circulating immature cells, mild or lack of splenomegaly, slow progressiveness, rather resistance to IFN-alpha, and good response to imatinib mesylate. This is the first report of BCR-a3-type CML in which the exact DNA breakpoint was identified and located between exons a2 and a3 of the ABL gene.
Chromosome Breakage , Fusion Proteins, bcr-abl/genetics , Genes, abl/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , RNA, Neoplasm , Disease Progression , Drug Resistance, Neoplasm , Exons , Humans , Introns , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Male , Middle Aged , Neoplastic Cells, Circulating , Phenotype , RNA, Messenger , Splenomegaly
